Ministers today ordered an investigation into a British hospital believed to have the longest waiting times in the developed world.

Patients reportedly have to wait up to nine years for treatment at the Welsh centre for burns and plastic surgery at Swansea's Morriston Hospital.

Welsh health minister Jane Hutt has now asked the specialist health services commission for Wales to carry out an immediate review.

A spokesman for Ms Hutt said: "The Welsh Assembly is aware that some patients have to wait an unacceptable length of time and there are issues surrounding the provision of plastic surgery at Morriston.

"We have asked for an urgent review of the requirements for services and the way they are delivered."

Non-emergency patients face a wait of up to nine years to see surgeon Bill Dickson.

Clinical director Hamish Laing has said that is the worst waiting time in the developed world.

Andrew Bellamy, director of corporate development at Swansea NHS Trust, blamed a shortage of surgeons for the problems.

He said the trust was holding talks with health authorities and the Welsh Assembly.

"It is a cause of great concern to clinicians and managers within the trust that waiting lists for plastic surgery are so long," he said.

"We need a significant increase in the number of plastic and reconstructive surgeons to cover the population served, but of course we will require a planned programme of investment to ensure the necessary facilities are available and that we are able to recruit for the service."

Some 40% of work carried out by the centre is for emergencies. Half of the elective surgery covers various forms of cancer.

Mr Bellamy said the emphasis on urgent work meant patients with a lower priority may have to wait longer for treatment.

The Assembly has set an in-patient waiting time target of 15 months. The trust is discussing ways of reaching the target with the health authorities, he said.

Trust chief executive David Williams said: "An awful lot of patients are waiting an unreasonable time for treatment."

Today's announcement comes as the Welsh Conservatives start their campaign for next May's Assembly election with a "health action day".

Welsh Tory health spokesman David Melding said the situation at Morriston was unacceptable.

"Any waiting list that is over a year or 18 months is completely unacceptable even for non-urgent surgery," he said.

"This is a record even for the Welsh NHS. These people have some level of disfigurement and it is very disturbing they have to wait six to nine years for non-urgent treatment. This is the most acute example, but it does reflect the long waiting lists across the NHS."